Continuous roll-to-roll patterning of three-dimensional periodic nanostructures

I-Te Chen,Chih-Hao Chang,Elizabeth Schappell,Xiaolong Zhang

doi:10.1038/s41378-020-0133-7

Abstract

In this work, we introduce a roll-to-roll system that can continuously print three-dimensional (3D) periodic nanostructures over large areas. This approach is based on Langmuir-Blodgett assembly of colloidal nanospheres, which diffract normal incident light to create a complex intensity pattern for near-field nanolithography. The geometry of the 3D nanostructure is defined by the Talbot effect and can be precisely designed by tuning the ratio of the nanosphere diameter to the exposure wavelength. Using this system, we have demonstrated patterning of 3D photonic crystals with a 500 nm period on a 50 × 200 mm2 flexible substrate, with a system throughput of 3 mm/s. The patterning yield is quantitatively analyzed by an automated electron beam inspection method, demonstrating long-term repeatability of an up to 88% yield over a 4-month period. The inspection method can also be employed to examine pattern uniformity, achieving an average yield of up to 78.6% over full substrate areas. The proposed patterning method is highly versatile and scalable as a nanomanufacturing platform and can find application in nanophotonics, nanoarchitected materials, and multifunctional nanostructures.

Highlights

Periodic three-dimensional (3D) nanostructures have been investigated in recent years according to their unique physical properties that only exist on the micro/ nanoscale
The nanospheres were removed before development, and the rainbow appearance is induced by the diffraction of the 3D photoresist structures
Note that the photoresist structure can act as a sacrificial template for subsequent material deposition processes such as physical vapor[34,36] or atomic layer deposition, which can yield 3D nanostructures in oxides or metals[10,14,15]

Summary

Introduction

Periodic three-dimensional (3D) nanostructures have been investigated in recent years according to their unique physical properties that only exist on the micro/ nanoscale. The distinct dispersion behavior of photonic crystals with periodic dielectric profiles can inhibit the propagation of photons with specific energy. 3D nanostructures can overcome the physical limitations observed for the mechanics of macroscale materials, leading to mechanical metamaterials with novel properties. Recent studies have shown that periodic nanoarchitected or nanolattice materials have more favorable density scaling of their stiffness and strength than random porous microstructures[7], can demonstrate larger recoverability[8,9,10], and can exhibit uncommon behaviors such as negative Poisson’s ratio or stiffness[11,12,13]

Methods

Results

Conclusion